The Festival Lanterns

A town's festival was lit by lanterns hanging on ropes strung between buildings.

Each rope held twenty lanterns. If one lantern caught fire, it burned through the rope.

One year, a lantern caught fire.

The rope snapped. The lanterns fell onto a market stall. The stall caught fire. The fire spread to the adjacent building. The building held oil for the other lanterns.

By morning, half the market district was ash.

The inquiry focused on who had made the faulty lantern. No one asked why all the lanterns were on the same rope.